SSL devices generally use semiconductor light emitting diodes (“LEDs”), organic light emitting diodes (“OLEDs”), laser diodes (“LDs”), and/or polymer light emitting diodes (“PLEDs”) as sources of illumination rather than electrical filaments, a plasma, or a gas. FIG. 1 is a cross-sectional diagram of a portion of a conventional indium gallium nitride (“InGaN”) LED 10. As shown in FIG. 1, the LED 10 includes a substrate material 12 (e.g., silicon carbide, sapphire, or silicon), an N-type gallium nitride (“GaN”) material 14, an active region 16 (e.g., GaN/InGaN multiple quantum wells (“MQWs”)), and a P-type GaN material 18 on top of one another in series. The LED 10 can also include a first contact 11 on the P-type GaN material 18 and a second contact 15 on the N-type GaN material 14.
The GaN/InGaN materials 14, 16, and 18 of the LED 10 are generally formed via epitaxial growth. The formed GaN/InGaN materials 14, 16, and 18, however, typically include a high density of lattice dislocations that can negatively impact the optical and/or electrical performance of the LED 10. For example, as described in more detail later, the formed GaN/InGaN materials 14, 16, and 18 can include a plurality of indentations that may form unintended carrier passages bypassing the active region 16 during processing.
One conventional technique for addressing the high density of lattice dislocations is to incorporate aluminum nitride (AlN), silicon nitride (SiN), and/or other suitable interlayers in the LED 10 (e.g., between the substrate 12 and the N-type gallium nitride 14). The incorporation of such interlayers, however, cannot completely eliminate the lattice dislocations in the GaN/InGaN materials 14, 16, and 18 of the LED 10. Also, incorporating interlayers adds cost and time to the manufacturing process of the LED 10. Accordingly, several improvements to at least lessen the impact of the lattice dislocations in LEDs may be desirable.